The present invention relates to a fuel system valve, and particularly to a valve with a sealing element resistant to deformation for regulating the flow of fuel vapor through a venting outlet.
Vehicle fuel systems are known to include valve assemblies mountable on fuel tanks or in filler necks of the vehicle fuel systems. Such conventional valve assemblies are typically manufactured of plastic materials and may include pressure-relief, over-fill, and/or rollover components. Further, the valve assemblies may include a sealing element made of a plastic, hard rubber, or other elastomeric material.
By way of example, in operation, the typical plastic sealing element presses against a portion of the plastic valve assembly under vapor or fuel pressure, gravity, or the like to seal the valve assembly. Over time, the recurring sealing action and repeated exposure to vehicle vibrations and fuel tank pressures can flatten and wear down edges of the plastic sealing element. Moreover, that portion of the valve assembly, which is contacted and sealed by the sealing element, may deteriorate such as by developing an indentation due to the repeated contact with the sealing element.
Eventual deformation of the plastic sealing element and the contacted portion of the valve assembly adversely affects the sealing capacity of the valve assembly. It will be appreciated, for instance, that impaired sealing can degrade the rollover function of the vehicle fuel system. Specifically, a deformed sealing element in a rollover situation can permit fuel to leak past an outlet of the valve assembly to a fuel vapor recovery canister or directly to the atmosphere external to the vehicle, which may create a fire or explosion hazard.
According to the present invention, a vehicle fuel vapor control valve is provided for use with a vehicle fuel system. The component parts of the invention are simple, reliable, and economical to manufacture, assemble, and use. Other advantages of the invention will be apparent from the following description and the attached drawings, or can be learned through practice of the invention.
According to an aspect of the invention, a fuel vapor control valve for regulating fuel vapor in a vehicle having a fuel tank and a recovery canister is provided. The fuel vapor control valve has a mounting portion with an inlet in communication with an inside of the fuel tank and an outlet for communicating fuel vapor from the fuel tank to the recovery canister.
The fuel vapor control valve in this aspect includes a rollover assembly, which has a valve housing and a valve member or float. The valve housing is configured for attachment to the mounting portion and has an opening in communication with the inlet of the mounting portion. The float is movable within the valve housing and has a structure and a seal depending from the float in a direction of the mounting portion. A skirt of the seal is retained with limited movement in a retention slot of the structure. Further, the retention slot has a contact surface and the skirt has a complimentary contact surface, which is configured to intermittently contact the contact surface as the seal releasably seals the opening. More specifically, the structure permits the seal to contact an area about the opening to releasably seal the opening when a level of fuel from the fuel tank contacts the float and urges the float in the direction of the mounting portion. Also in this aspect, the seal is made of a metallic material while the valve housing is an plastic material. The foregoing construction prevents deformation of the seal and the valve housing due to repeated contact by the seal against the contact surface when sealing the valve assembly.
According to another aspect of the invention, a rollover valve assembly, in some ways similar to the previous example, has a valve member movable in a chamber of a housing. The valve member in this aspect has a point-bearing surface on which a sealing element is movably located to releasably seal an opening in the housing when the valve member is urged in a direction towards the opening by rising fuel, gravity or the like.
The sealing element in this aspect has an insert (alternatively, receptacle) with a receiving surface, which may be cone-shaped to receive the point-bearing surface. The sealing element defines a substantially flat surface and a skirt disposed apart from the flat surface. The insert is affixed in the sealing element such that the skirt moves with a movement of the insert on the point-bearing surface. Accordingly, the flat surface releasably seals the opening when, for example, the fuel rises to urge the valve member toward the opening while permitting the valve member a limited range of motion about the sealing element when it is sealed against the opening.
Also in this aspect of the invention, the flat surface and the skirt of the sealing element are manufactured of a metallic material and the receptacle is manufactured from a plastic or elastomeric material. However, the flat surface, skirt and the receptacle can be unitarily constructed of metal, which can be stainless steel, aluminum, a non-corrosive alloy or combinations of these or other metals.
In another aspect of the invention, a rollover valve assembly similar to the foregoing embodiments has a housing, which is mountable to a fuel tank. The rollover valve assembly also includes a valve member movable in a chamber of the housing. A metallic sealing element is located on the valve member to releasably seal an opening in the housing in communication with the chamber when the valve member is urged in a direction toward the opening.
Moreover, the housing defines a plastic surface disposed about the opening, and the metallic sealing element defines a substantially flat surface configured to substantially uniformly contact the plastic surface and seal about the opening when the valve member is urged in the direction by a force such as rising fuel, gravity, a spring constant or the like. In this aspect, the flat surface of the metallic sealing element is polished such that it is substantially smooth and flat. This construction provides a flat, hard metal part, which, when contacting the sealing surface repeatedly, provides for a flat sealing surface and a tight seal. More specifically, because the flat metal surface does not deform the plastic sealing surface such as with grooves and indentations, the seal created by the metal sealing element to plastic sealing surface tends to produce a tighter seal than a plastic-to-plastic or metal-to-metal combination.
Another aspect of the invention includes a fuel vapor control valve for a fuel system, which has a fuel tank and a connection portion attached to a fuel vapor recovery canister. This example fuel vapor control valve includes a valve housing configured for attachment to the connection portion and a valve member, similar to the foregoing descriptions, which is axially movable in the valve housing. Further, the valve housing includes a first opening, a second opening and a disc holder or pocket. The first opening communicates with the fuel tank while the second opening communicates with the fuel vapor recovery canister. The disc holder is located between the connection portion and the second opening to hold a vapor restriction device such as a disc, which is movably seated in the disc holder. At least one hole in the disc is configured to permit a restricted passage of fuel vapor substantially at all times when the disc is normally seated in the holder. In some circumstances, the disc holder permits the disc to rise up momentarily to increase fuel vapor flow.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the attached drawings in conjunction with the following detailed description of the drawings, which exemplifies the best mode of carrying out the invention as presently perceived, or can be learned through practice of the invention.